Alright, guys, so after some deliberation (and after exploring a couple of the options personally), we're going with Geometry Wars 2's Deadline mode.
Deadline mode is basically a Geometry Wars caravan mode. It has a three-minute timer and infinite lives (bombs are awarded the same way they are in other modes). You shouldn't take advantage of the infinite lives, though - the longer you survive on a single life, the more intense the waves get, and the greater the scoring potential.
Geometry Wars 2 is 400MSP on XBLA, and Deadline is the first mode available. If it's an option for anyone aside from me, I'll also accept scores from Geometry Wars: Touch, the iOS version, as it's just a port of GW2 with an extra mode added, and only costs ninety-nine cents. Just make sure you take a screenshot.
The Deadline deadline is Christmas.
